Whenever work is done on or near the roadway, drivers are faced with Changing and unexpected traffic conditions. These changes may be hazardous for drivers, workers and pedestrians unless protective measures are taken.

Drivers and pedestrians should take special care to observe signs, signals, pavement markings and flagmen, near roadway construction sites. These traffic control devices are installed to assist and safely guide and protect motorists, pedestrians and workers in a traffic control zone.

Most traffic control zones are divided into the following areas:

   - Advance Warning Area - tells traffic what to expect.

   - Transition Area - moves traffic out of its normal area.

   - Buffer Space - provides protection for traffic and workers.

   - Work Area - closed to traffic and set aside for workers, equipment and material.

   - Termination Area - lets traffic resume normal driving.

Regulatory Signs are typically rectangular in shape with the long dimension vertical. The standard color schemes is black lettering on a white background. A red circle with a diagonal slash may be used in conjunction with a black diagram to indicate a prohibited maneuver. Red is used as a predominant color for STOP, YIELD, DO NOT ENTER and WRONG WAY signs.

Warning Signs are used to give notice of conditions that are potentially hazardous to traffic. These signs are used particularly when the danger is not obvious or cannot be seen by the motorist. Warning signs are typically diamond-shaped with one diagonal vertical. Permanent warning signs have a black legend on an orange background. The orange color is used to indicate the temporary nature of the condition and the additional potential hazard of the work site. Traditionally, work activities have included construction, maintenance, and utility operations. However, orange color warning signs may have application for all work activities within the right of way such as survey crews or temporary weighing stations.

Guide Signs show destinations, directions, distances, services, points of interest and other geographical information. Directional signs and street name signs, when used with detour routing, may have a black legend on an orange background. Special information signs relating to the work being done shall have a black message on an orange background.